US8537076B2 - Video circuit - Google Patents
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- US8537076B2 US8537076B2 US10/524,968 US52496803A US8537076B2 US 8537076 B2 US8537076 B2 US 8537076B2 US 52496803 A US52496803 A US 52496803A US 8537076 B2 US8537076 B2 US 8537076B2
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- 230000015654 memory Effects 0.000 claims abstract description 94
- 230000007704 transition Effects 0.000 claims abstract description 5
- 238000013139 quantization Methods 0.000 claims description 73
- 230000006870 function Effects 0.000 claims description 26
- 238000000034 method Methods 0.000 claims description 14
- 230000008569 process Effects 0.000 claims description 10
- 238000006243 chemical reaction Methods 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 13
- 238000006467 substitution reaction Methods 0.000 description 7
- 238000001514 detection method Methods 0.000 description 3
- 238000000790 scattering method Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000008447 perception Effects 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 1
- 230000001934 delay Effects 0.000 description 1
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/2007—Display of intermediate tones
- G09G3/2059—Display of intermediate tones using error diffusion
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/2007—Display of intermediate tones
- G09G3/2018—Display of intermediate tones by time modulation using two or more time intervals
- G09G3/2022—Display of intermediate tones by time modulation using two or more time intervals using sub-frames
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
- G09G3/28—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels
- G09G3/288—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels using AC panels
- G09G3/291—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels using AC panels controlling the gas discharge to control a cell condition, e.g. by means of specific pulse shapes
- G09G3/294—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels using AC panels controlling the gas discharge to control a cell condition, e.g. by means of specific pulse shapes for lighting or sustain discharge
- G09G3/2948—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels using AC panels controlling the gas discharge to control a cell condition, e.g. by means of specific pulse shapes for lighting or sustain discharge by increasing the total sustaining time with respect to other times in the frame
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/14—Picture signal circuitry for video frequency region
- H04N5/20—Circuitry for controlling amplitude response
- H04N5/202—Gamma control
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/66—Transforming electric information into light information
- H04N5/70—Circuit details for electroluminescent devices
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/02—Improving the quality of display appearance
- G09G2320/0271—Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/02—Improving the quality of display appearance
- G09G2320/0271—Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
- G09G2320/0276—Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/01—Conversion of standards, e.g. involving analogue television standards or digital television standards processed at pixel level
- H04N7/0117—Conversion of standards, e.g. involving analogue television standards or digital television standards processed at pixel level involving conversion of the spatial resolution of the incoming video signal
- H04N7/012—Conversion between an interlaced and a progressive signal
Definitions
- the invention relates to a video circuit for processing video signals which show images on a display panel with linear light transition, comprising a gamma correction circuit, a quantizer and a sub-field generator circuit.
- video signals for showing images on a display panel of a television set comprise a red, a green and a blue signal, which is 3 times 8 bits of video data.
- Plasma display panel or PDP for short have a linear light transition. Therefore, the video signals subjected to a gamma function are to be corrected and the video signals converted into luminance data.
- Plasma display panels are limited as regards the number of luminance stages that can be displayed, a quantization process therefore reduces the number of bits. For generating red, green or blue light for a pixel, sub-fields are addressed which make a red, green or blue light source of the pixel light up for the definite period.
- This technique is also referred to as sub-field generation or SFG for short.
- Processors are provided for these methods.
- the conversion of video signals into luminance signals, the quantization method and the addressing of sub-fields are methods requiring time and implemented successively for a plasma display panel. If a movement occurs from one picture to the next, artefacts may occur.
- a coarse adjustment of the quantization is effected and in a second random-access memory a fine adjustment.
- Time is saved with the quantization effected in a random-access memory.
- most significant bits are quantized in a first random-access memory and least significant bits are quantized in a second random-access memory.
- Time is saved with the quantization effected in a random-access memory.
- the splitting-up into two parts significantly reduces the necessary memory size for a 12-bit input.
- a random-access memory replaces the quantizer. Digital data signals are applied to a random-access memory as addresses and associated values are issued from an output. This saves time compared to a computer that carries out calculations in a plurality of steps.
- the random-access memory advantageously replaces a dequantizer.
- the formerly quantized signal is reconverted and a comparison with the input values can be made.
- Quantizers and dequantizers are realized in a random-access memory.
- a quantization error can be detected and an error scattering method can be performed by means of a filter.
- An inverse gamma correction circuit is advantageously included downstream of the dequantizer. If the correction in the gamma correction circuit is not converted with equidistant values, the inverse gamma correction circuit is necessary between the dequantizer and the filter. The quantizer, the dequantizer, the gamma correction circuit and the inverse gamma correction circuit are then realized in a single random-access memory.
- the random-access memory advantageously replaces a sub-field generator. If the quantizer, dequantizer and sub-field generator are collectively realized in a single random-access memory, computer time is also saved.
- a gamma function, a quantization, a sub-field generation circuit and a partial line doubling are advantageously achieved by means of two random-access memories. Least significant bits of sub-fields of two neighboring lines are identical and time is saved then.
- the sub-field generator circuit of a first random-access memory outputs a bit sample with which a plasma display panel can be driven directly and furthermore outputs data via a converter, a quantizer and a filter to the input signal of the neighboring line and via a second converter, a second dequantizer also to the input signal. With sub-fields that are spread non-equidistantly by the bit sample of the least significant bits is output directly to the quantizer of the second random-access memory.
- FIG. 1 shows a block circuit diagram comprising a random-access memory for a quantization process and subsequent dequantization process
- FIG. 2 shows a display panel section with neighboring pixels
- FIG. 3 shows the display panel section with correction values for the neighboring pixels
- FIG. 4 shows a filter with delay elements
- FIG. 5 shows a block circuit diagram with two random-access memories for a coarse and a fine adjustment of a quantization process
- FIG. 6 shows a block circuit diagram with two random-access memories for most significant and least significant bits of a quantization process
- FIG. 7 shows a block circuit diagram with a random-access memory which replaces a gamma correction function and a quantization process for equidistant values
- FIG. 8 shows a block circuit diagram with a random-access memory which replaces a gamma correction function and a quantization process and their reverse functions for non-equidistant values
- FIG. 9 shows a diagram for the representation of quantization noise with a classification in equidistant values
- FIG. 10 shows a diagram for the representation of quantization noise for a classification in non-equidistant values
- FIG. 11 shows a block circuit diagram with a random-access memory which replaces a gamma correction function, a quantizer and their reverse functions and a sub-field generator,
- FIG. 12 shows a block circuit diagram for a partial line doubling
- FIG. 13 shows a block circuit diagram with two random-access memories for processing pixel values of a first and a second line for equidistant sub-line codings
- FIG. 14 shows a block circuit diagram with two random-access memories for processing pixel values of a first and a second line for non-equidistant sub-field codings
- FIG. 15 shows a timing diagram with sub-fields for the operation of a plasma display panel
- FIG. 16 shows a second timing diagram with sub-fields for the operation of a plasma display panel in which a partial line doubling is used.
- FIG. 1 shows a video circuit 1 having an input 2 , a gamma correction circuit 3 , an adder 4 , a memory 5 , a rounding circuit 6 , a random-access memory 7 , a sub-field generator circuit 8 also called sub-field generation or SFG circuit for short, an output 9 and a filter 10 .
- the memory 7 replaces a multiplier circuit 11 , a rounding circuit 12 , a second multiplier circuit 13 and an adding circuit 14 .
- the random-access memory 7 is also referred to as allocation table or look-up table, LUT for short. For defined values on m-defined lines the initial values which are present as a result of the functions combined in the memory 7 are calculated and stored in the memory 7 .
- FIG. 2 shows a display section with neighboring pixels x ⁇ 1, y ⁇ 1 and x, y ⁇ 1 and x+1, y ⁇ 1 and x ⁇ 1, y and x, y. Then x is a substitute for the number of the column and y is a substitute for the number of the line.
- FIG. 3 shows absolute values by which a quantization error QE which occurs at the respective spot is multiplied for the generation of a value to be displayed for a current value in a pixel x, y.
- the quantization error, QE for short, is also referred to as quantization noise.
- FIG. 4 shows the filter 10 comprising delay elements 15 - 18 and multiplier elements 19 - 22 and adders 23 , 24 , 25 .
- the elements 15 , 17 and 18 each delay by one pixel and have a memory location for the value of one pixel, the delay element 16 delays by the number of pixels of one line, subtracts two pixels and accordingly has many memory locations.
- the function of the video circuit 1 can be described as follows: in the gamma correction circuit 3 a red, green or blue signal is converted into a red, green or blue luminance signal under the influence of a gamma function.
- the converted red, green or blue luminance signal is applied to the adder 4 over a parallel data line comprising m or 12, respectively, lines.
- a value 1 ⁇ 2 from the memory 5 and a further value which is the sum of quantization noise from previous pixels are added to the luminance signal in the adder 4 .
- a luminance value of a pixel value to be displayed is thus calculated as the sum of a current pixel value X (x,y) which is present at input 2 and of the pixel values neighboring the quantization noise values, which neighboring pixel values are calculated in the filter 10 and are added to the current value.
- pixel value to be displayed rounded ( X (x,y) +1 ⁇ 2+ 1/16QE (x ⁇ 1,y ⁇ 1) + 5/16QE (x,y ⁇ 1) + 3/16QE (x+1,y ⁇ 1) + 7/16QE (x ⁇ 1,y) ) with the current pixel value X (x,y) . with the value 1 ⁇ 2 from the memory 5 and with the values 1/16QE (x ⁇ 1,y ⁇ 1) + 5/16QE (x,y ⁇ 1) + 3/16QE (x+1,y ⁇ 1) + 7/16QE (x ⁇ 1,y) as a total sum from filter 10 .
- the influence on the current pixel value X (x,y) by the filter values is also known as the Floyd-Steinberg algorithm.
- the random-access memory 7 replaces the two multiplications 11 and 13 , the rounding function 12 and the addition 14 . This means that for m addresses memory values are available for n outputs to the SFG circuit 8 and m+1 ⁇ n outputs to the filter 10 , which are all in all 2 m * (m+1) memory locations.
- FIG. 5 shows a second video circuit 31 having an input 2 , the gamma correction circuit 3 , the adder 4 , the memory 5 , the rounding circuit 6 , the SFG circuit 8 , the output 9 , the filter 10 and a circuit 32 .
- the circuit 32 has a coarse-value random-access memory 33 , a fine-value random-access memory 34 and two adders 35 and 36 .
- the coarse-value random-access memory 33 performs a coarse adjustment in the quantization for the output and the fine-value random-access memory 34 a fine adjustment in the quantization for the output and a feedback loop 37 .
- the look-up table is split up into two sub-memories 33 and 34 and the necessary memory size is significantly reduced by 0.8 kbyte for a 12-bit input.
- FIG. 6 shows a further video circuit 41 having the input 2 , the gamma correction circuit 3 , the adder 4 , the memory 5 , the rounding circuit 6 , the SFG circuit 8 , the output 9 , the filter 10 and a circuit 42 .
- the circuit 42 has an MSB random-access memory 43 , an LSB random-access memory 44 and two adders 45 and 46 .
- MSB is the abbreviation of most significant bits, thus high-order bits, LSB stands for least significant bits, low-order bits.
- the input data stream of the parallel data is divided into two halves, where m-k parallel data, which corresponds to m-k parallel lines, flow as MSB into the first memory 43 and 2 m-k addresses are detected there. A second half k of parallel data, which corresponds to k parallel lines, flows into the memory 44 .
- a quantization error is further subtracted in the adder 46 from the LSB data.
- circuit 42 The function of the circuit 42 is explained for simplicity with values from the decimal system and is as follows.
- the value 41 should be present on the output of circuit 41 .
- output values for MSB input values are issued in tens, thus in steps of ten and in the LSB random-access memory 44 output values for LSB input values are issued in steps of one.
- the MSB memory 43 cannot supply the value 40 , but only 39 , a quantization error QE occurs on the output of the MSB memory 43 , which also flows into the LSB memory 44 via the adder 46 .
- the necessary memory size is reduced by 0.25 kbyte for a 12-bit input.
- the random-access memory is divided into two parts, one part generates an MSB quantization and an associated quantization error on a first output and the other part generates the LSB quantization and an associated quantization error on a second output. If the two output signals are added together, this will lead to the new quantized value.
- the size of the MSB random-access memory is 2 m/2+(m+1)
- the size of the LSB random-access memory is 2 (m+1)/2+(m+1)
- the new quantization output signal is: Rounded (1 ⁇ 2 n +1 /S *rounded ( X (x,y) +1 ⁇ 2 m + 1/16QE (x ⁇ 1,y ⁇ 1) + 5/16QE (x,y ⁇ 1) + 3/16QE (x+1,y ⁇ 1) + 7/16QE (x ⁇ 1,y) ))
- the new quantization error is: Rest (1 ⁇ 2 n +1 /S *rounded ( X (x,y) +1 ⁇ 2 m + 1/16QE (x ⁇ 1,y ⁇ 1) + 5/16QE (x,y ⁇ 1) + 3/16QE (x+1,y ⁇ 1) + 7/16QE (x ⁇ 1,y) ))
- FIG. 7 shows a video circuit 51 comprising a random-access memory 52 in which a gamma correction function 53 and a quantization function 54 are combined.
- the gamma correction function 53 is converted with equidistant values, so that the error spreading in the luminance area is effected by means of a forward controller 55 .
- a current value from the luminance area is added to the filter value from the filter 10 in an adder 57 .
- FIG. 8 shows a video circuit 61 comprising a random-access memory 62 for values converted with non-equidistant values.
- the memory 62 replaces a gamma correction circuit 63 , a quantizer 64 , a dequantizer 65 , an inverse gamma correction circuit 66 and an adder 67 . Since the gamma-corrected values in the gamma correction circuit 63 have been converted with non-equidistant values, an inverse gamma correction circuit 66 is included in a feedback loop 68 . A rounding circuit 69 is inserted between the filter 10 and the adder 4 .
- FIG. 9 shows a gamma curve 71 which is converted with equidistant values.
- the result is a quantization noise curve 72 with a high quantization error in a dark area between the absolute values 1 and 22. Especially in dark areas the perception by the human eye is better than in bright areas. The high quantization error is thus perceived by a viewer. This provides a discrepancy between sampling and perception.
- FIG. 10 shows a gamma curve 81 which is sampled with non-equidistant values.
- the non-equidistant values are shown as curve 82 .
- a quantization noise curve 83 with a rather large quantization noise in a dark area between the absolute values 1 and 22 is smaller than the QE in values converted equidistantly.
- the first value in the dark area has a small quantization error.
- the quantization noise is larger.
- the quantization noise in bright areas can be perceived less by a viewer.
- the sample values thus correspond to the observation.
- FIG. 11 shows a video circuit 101 comprising a random-access memory 102 which replaces the gamma correction circuit 63 , the quantizer 64 , the dequantizer 65 , the inverse gamma correction circuit 66 , the addition 67 and the sub-field generator 8 .
- FIG. 12 shows a circuit 111 comprising a line delay 112 , a min/max detection circuit 113 , a first substitution circuit 114 , a partial line doubling circuit 115 and a second substitution circuit 116 .
- the line of a television picture is delayed by one line in the delay circuit 112 .
- values of two pixels lying beside each other in one column are compared in the detection circuit 113 .
- the respective larger value is defined and applied to a first or second input of the doubling circuit 115 . If the lines are then substituted in the substitution circuit 114 , a re-substitution is made in the second substitution circuit 116 .
- FIG. 13 shows a first partial line doubling circuit 120 for equidistant sub-field codings which circuit can be used for the partial line doubling circuit 115 , comprising a first gamma correction circuit 121 , an adder 122 , an inverse gamma correction circuit 123 , a memory 124 , a 2D filter 125 , a further gamma correction circuit 126 , a further adder 127 , an inverse gamma correction circuit 128 , a further memory 129 and a one-dimensional filter 130 .
- the memory 124 replaces a gamma correction circuit 131 , a quantizer 132 , an SFG and a PLD circuit 133 , a converter 134 , a dequantizer 135 , a second converter 136 , a second dequantizer 137 and an adder 138 .
- the SFG and PLD circuit 133 includes an MSG circuit 139 , an LSG circuit 140 , an LSG light circuit 141 and a QE circuit 142 .
- the memory 129 replaces a gamma correction circuit 143 , a quantizer 144 , an SFG and PLD circuit 145 , a further converter 146 , a dequantizer 147 and an adder 148 .
- the SFG and PLD circuit 145 includes an MSG circuit 149 and a QE circuit 150 . Signals are present on inputs 151 and 152 and output signals are output via the outputs 153 , 154 , 155 and 156 .
- This partial line doubling circuit 120 can be used instead of the partial line doubling circuit 115 .
- FIG. 14 shows a second partial line doubling circuit 159 for non-equidistant sub-field codings, which circuit 159 can be used instead of the partial line doubling circuit 115 , with an adder 160 , a memory 161 , a 2D filter 162 , a further adder 163 , a further memory 164 and a one-dimensional filter 165 .
- the memory 161 replaces a gamma correction circuit 166 , a quantizer 167 , an SFG and PLD circuit 168 , a converter 169 , a dequantizer 170 , an inverse gamma correction circuit 171 and an adder 172 .
- the SFG and PLD circuit 168 includes an MSG circuit 173 , an LSG circuit 174 and a QE circuit 175 .
- the memory 164 replaces a gamma correction circuit 176 , a quantizer 177 , an SFG and PLD circuit 178 , a converter 179 , a dequantizer 180 , an inverse gamma correction circuit 181 and an adder 182 .
- the SFG and PLD circuit 178 includes an MSG circuit 183 and a QE circuit 184 . Signals are present on inputs 185 and 186 and output signals are output via outputs 187 , 188 , 189 and 190 .
- FIG. 15 shows eight sub-fields 201 to 208 , SF for short.
- Each sub-field has an erasing time 209 , an addressing time 210 and a sustaining time 211 .
- the eight sub-fields cover a picture duration 212 .
- the sub-fields 201 to 204 represent least significant bits of a group or LSB for short of a least significant group or LSG for short.
- the sub-fields 205 to 208 represent most significant bits or MSB of a most significant group or MSG.
- LSB for two successive lines are identical, there is a time-saving 213 as shown in FIG. 16 .
- the doubling of partial ranges of a line is called partial line doubling in English, PLD for short. Only during the stop period are emitted light pulses from the red, green or blue light sources of a pixel.
- the function of the circuit 120 is as follows: pixel values are present on the input of the memory 124 and are converted in the gamma correction circuit 131 into the luminance area, therefore, an 8-bit data word becomes an 12-bit data word to achieve a sufficiently high resolution in dark areas.
- the 12-bit data word is adapted to a data word that is necessary for the sub-field generation.
- the latter data word is applied to the SFG and PLD circuit 133 and an associated bit sample of sub-fields is generated in this circuit.
- the quantization error is applied to the 2D filter 125 and filtered in accordance with the Floyd-Steinberg algorithm. Since the filtered quantization error is situated in the luminance area and is to be applied to the input signal, the input signal is transformed into the luminance area by the gamma correction circuit 121 . This transformation is cancelled in the inverse gamma correction circuit 123 .
- the filter 125 is connected via an electrically conductive line to the adder 127 .
- an output signal of the 2D filter is added for further processing to an input signal which represents pixel values of the neighboring line.
- a respective correction signal is transported from the LSG circuit 141 via the converter 136 , the dequantizer 137 to the adder 127 and thus the input signal is corrected which represents pixel values of pixels of the neighboring line.
- the video signals in the gamma correction circuit 143 in the memory 129 are transformed from the video area into the luminance area, then quantized in the quantizer 144 and conveyed to an SFG and PLD circuit 145 which generates the bit sample for the sub-fields of the PDP. Only the MSG are generated then.
- a light value signal is reconverted in the converter circuit 146 into a luminance signal and a possible addressing error is eliminated.
- the luminance signal is dequantized in the dequantizer 147 and applied to the adder 148 . In the adder is determined an actual quantization error and applied to the filter 130 .
- the quantization error has no effect on neighboring lines, so that only a one-dimensional filter 130 is used.
- the adder 127 is surrounded by a gamma correction circuit 126 and an inverse gamma correction circuit 128 which convert the values of the current pixel of the second neighboring line.
- the function of the circuit 159 can be described as follows: pixel values are present on an input 185 of the circuit 159 and are converted into the luminance area in the gamma correction circuit 166 and for this purpose an 8-bit data word becomes a 12-bit data word to achieve a sufficiently high resolution in dark areas.
- the 12-bit data word is adapted to a data word that is necessary for the sub-field generation. This data word is applied to the SFG and PLD circuit 168 and in this circuit an associated bit sample of sub-fields is generated which is output via the outputs 187 and 188 .
- the filter 162 is connected to the adder 163 via an electrically conducting line.
- an output signal of the 2D filter is added to an input signal for further processing which input signal represents pixel values of the neighboring line.
- the video signals in the gamma correction circuit 176 are transformed from the video area to the luminance area, then quantized in the quantizer 177 and conveyed to an SFG and PLD circuit 178 which generates the sub-fields for the PDP. Only the MSG are generated then.
- the converter circuit 179 a light value signal is reconverted into a luminance signal and a possible addressing error is eliminated.
- the luminance signal is dequantized in the dequantizer 180 and applied to the inverse gamma correction circuit 181 .
- the adder 182 is detected an actual quantization error and this error is applied to the filter 165 .
- the quantization error has no effect on neighboring lines so that only a one-dimensional filter 165 is used.
- the LSB on the output 188 are directly applied to the quantizer 177 and are thus taken into account when the most significant bits of the neighboring line available on output 189 are formed.
Abstract
Description
pixel value to be displayed=rounded (X (x,y)+½+ 1/16QE(x−1,y−1)+ 5/16QE(x,y−1)+ 3/16QE(x+1,y−1)+ 7/16QE(x−1,y))
with the current pixel value X(x,y).
with the value ½ from the
with the
F(x)=(x/S)
where S is the quantization factor that is calculated as follows
S=number of input stages/number of output stages=1024/256=4
The dequantization function is predefined by
F(y)=y*S
The influence on the current pixel value X(x,y) by the filter values is also known as the Floyd-Steinberg algorithm. The random-
LSB−(−1)=LSB+1=2.
(X (x,y)+½+ 1/16QE(x−1,y−1)+ 5/16QE(x,y−1)+ 3/16QE(x+1,y−1)+ 7/16QE(x−1,y))
X is the value of the newly arriving pixel and QE is the quantization error of previously generated pixel values.
Rounded (½n+1/S*rounded (X (x,y)+½m+ 1/16QE(x−1,y−1)+ 5/16QE(x,y−1)+ 3/16QE(x+1,y−1)+ 7/16QE(x−1,y)))
Rest (½n+1/S*rounded (X (x,y)+½m+ 1/16QE(x−1,y−1)+ 5/16QE(x,y−1)+ 3/16QE(x+1,y−1)+ 7/16QE(x−1,y)))
1 | video circuit | 32 | circuit |
2 | input | 33 | coarse-value random-access |
memory | |||
3 | gamma correction circuit | 34 | fine-value |
random-access memory | |||
4 | adder | 35 | adder |
5 | memory | 36 | adder |
6 | rounding circuit | 37 | feedback loop |
7 | random-access memory | 38 | |
8 | sub-field generator circuit | 39 | |
9 | output | 40 | |
10 | filter | 41 | video circuit |
11 | multiplier circuit | 42 | circuit |
12 | rounding circuit | 43 | MSB random-access memory |
13 | second multiplier circuit | 44 | LSB random-access memory |
14 | adder circuit | 45 | adder |
15 | delay element | 46 | adder |
16 | delay element | 47 | |
17 | delay element | 48 | |
18 | delay element | 49 | |
19 | multiplier element | 50 | |
20 | multiplier element | 51 | video circuit |
21 | multiplier element | 52 | random-access memory |
22 | multiplier element | 53 | gamma correction circuit |
23 | adder | 54 | quantizer |
24 | adder | 55 | forward controller |
25 | adder | 56 | delay element |
26 | 57 | adder | |
27 | 58 | ||
28 | 59 | ||
29 | 60 | ||
30 | 61 | video circuit | |
31 | video circuit | 62 | random-access memory |
63 | gamma correction circuit | 94 | |
64 | quantizer | 95 | |
65 | dequantizer | 96 | |
66 | inverse gamma | 97 | |
correction circuit | |||
67 | adder | 98 | |
68 | feedback loop | 99 | |
69 | rounding circuit | 100 | |
70 | 101 | video circuit | |
71 | gamma curve | 102 | random-access memory |
72 | quantization noise curve | 103 | sub-field generation |
73 | 104 | ||
74 | 105 | ||
75 | 106 | ||
76 | 107 | ||
77 | 108 | ||
78 | 109 | ||
79 | 110 | ||
80 | 111 | circuit | |
81 | gamma curve | 112 | line delay |
82 | curve | 113 | Min/Max detection circuit |
83 | quantization noise curve | 114 | substitution circuit |
84 | 115 | partial line doubling circuit | |
85 | 116 | second substitution circuit | |
86 | 117 | ||
87 | 118 | ||
88 | 119 | ||
89 | 120 | partial line doubling circuit | |
90 | 121 | gamma correction circuit | |
91 | 122 | adder | |
92 | 123 | inverse gamma | |
correction circuit | |||
93 | 124 | memory | |
125 | 2D filter | 157 | |
126 | gamma correction circuit | 158 | |
127 | adder | 159 | second partial line |
doubling circuit | |||
128 | inverse gamma | 160 | adder |
correction circuit | |||
129 | memory | 161 | memory |
130 | one-dimensional filter | 162 | 2D filter |
131 | gamma correction circuit | 163 | adder |
132 | quantizer | 164 | memory |
133 | SG ad PLD circuit | 165 | one-dimensional filter |
134 | converter | 166 | gamma correction circuit |
135 | dequantizer | 167 | quantizer |
136 | converter | 168 | SFG and PLD circuit |
137 | second dequantizer | 169 | converter |
138 | adder | 170 | dequantizer |
139 | MSG circuit | 171 | inverse gamma |
correction circuit | |||
140 | LSG circuit | 172 | adder |
141 | LSG light circuit | 173 | MSG circuit |
142 | QE circuit | 174 | LSG circuit |
143 | gamma correction circuit | 175 | QE circuit |
144 | quantizer | 176 | gamma correction circuit |
145 | SFG and PLD circuit | 177 | quantizer |
146 | inverse luminance circuit | 178 | SFG and PLD circuit |
147 | dequantizer | 179 | converter |
148 | adder | 180 | dequantizer |
149 | MSG circuit | 181 | inverse gamma |
correction circuit | |||
150 | QE circuit | 182 | adder |
151 | input | 183 | MSG circuit |
152 | input | 184 | QE circuit |
153 | output | 185 | input |
154 | output | 186 | input |
155 | output | 187 | output |
156 | output | 188 | output |
189 | output | 221 | |
190 | output | 222 | |
191 | 223 | ||
192 | 224 | ||
193 | 225 | ||
194 | 226 | ||
195 | 227 | ||
196 | 228 | ||
197 | 229 | ||
198 | 230 | ||
199 | 231 | ||
200 | 232 | ||
201 | sub-field | 233 | |
202 | sub-field | 234 | |
203 | sub-field | 235 | |
204 | sub-field | 236 | |
205 | sub-field | 237 | |
206 | sub-field | 238 | |
207 | sub-field | 239 | |
208 | sub-field | 240 | |
209 | erasing time | ||
210 | addressing time | ||
211 | sustaining time | ||
212 | duration of image | ||
213 | time saving | ||
214 | |||
215 | |||
216 | |||
217 | |||
218 | |||
219 | |||
220 | |||
Claims (8)
PVTBD=rounded (X (x,y)+CV+α×QE(X (x−1,y−1))+b×QE(X (x,y−1))+c×QE(X (x+1,y−1))+d×QE(X (x−1,y)),
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP02078419 | 2002-08-19 | ||
EP02078419.5 | 2002-08-19 | ||
EP02078419 | 2002-08-19 | ||
PCT/IB2003/003324 WO2004017287A2 (en) | 2002-08-19 | 2003-07-24 | Video circuit |
Publications (2)
Publication Number | Publication Date |
---|---|
US20050253784A1 US20050253784A1 (en) | 2005-11-17 |
US8537076B2 true US8537076B2 (en) | 2013-09-17 |
Family
ID=31725470
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/524,968 Expired - Fee Related US8537076B2 (en) | 2002-08-19 | 2003-07-24 | Video circuit |
Country Status (6)
Country | Link |
---|---|
US (1) | US8537076B2 (en) |
EP (1) | EP1565901A2 (en) |
JP (1) | JP2005536924A (en) |
CN (1) | CN1705970A (en) |
AU (1) | AU2003249428A1 (en) |
WO (1) | WO2004017287A2 (en) |
Families Citing this family (9)
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EP1439517A1 (en) * | 2003-01-10 | 2004-07-21 | Deutsche Thomson-Brandt Gmbh | Method and device for processing video data for display on a display device |
CN100428292C (en) * | 2004-05-12 | 2008-10-22 | 钰创科技股份有限公司 | Full gain compensate control system and method for gamma collection in display controller |
KR100634731B1 (en) * | 2005-01-11 | 2006-10-16 | 엘지전자 주식회사 | Image Processing Device and Method for Plasma Display Panel |
CN101123667B (en) * | 2006-08-11 | 2010-05-12 | 致伸科技股份有限公司 | Image processing method and device |
KR20080048894A (en) * | 2006-11-29 | 2008-06-03 | 엘지전자 주식회사 | Flat display device and driving method of the same |
JP4922091B2 (en) * | 2007-07-23 | 2012-04-25 | ルネサスエレクトロニクス株式会社 | Video signal processing device, video signal processing method, and display device |
JP2009081812A (en) * | 2007-09-27 | 2009-04-16 | Nec Electronics Corp | Signal processing apparatus and method |
KR20100039743A (en) * | 2008-10-08 | 2010-04-16 | 삼성전자주식회사 | Display apparatus and method of displaying thereof |
JP4577590B2 (en) | 2008-10-22 | 2010-11-10 | ソニー株式会社 | Image processing apparatus, image processing method, and program |
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Also Published As
Publication number | Publication date |
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AU2003249428A8 (en) | 2004-03-03 |
US20050253784A1 (en) | 2005-11-17 |
AU2003249428A1 (en) | 2004-03-03 |
EP1565901A2 (en) | 2005-08-24 |
WO2004017287A2 (en) | 2004-02-26 |
JP2005536924A (en) | 2005-12-02 |
WO2004017287A3 (en) | 2005-06-30 |
CN1705970A (en) | 2005-12-07 |
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